The present invention relates to an apparatus for operating and positioning a window shade. In particular, the present invention relates to a manually operated shade positioning system incorporating an integral clutch mechanism which maintains the shade roller in the desired position but which may be easily overridden by the user when the shade is desired to be repositioned.
The prior art contains a variety of shade operator systems which utilize a variety of mechanisms for maintaining a window shade at a desired position. For example, U.S. Pat. No. 4,424,852 of Jan. 10, 1984 to Hopper utilizes a bead-chain drive system in which the bead-chain is provided with a moveable retainer which counteracts the rotative force applied to the shade roller by the weight of the shade. The retainer is positionable along the length of the bead-chain as required to allow adjustment of the shade. Such an apparatus, however, requires the utilization of a bead-chain cord, and further relies upon the weight of the shade to maintain tension in the bead-chain such that the retainer is maintained in position.